[BUG] Named sessions not appearing in /resume picker

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

Summary:
Sessions renamed using /rename do not appear in the /resume interactive picker, even though they exist on disk and can be resumed directly by session ID.

Environment:

• Claude Code version: 2.1.31
• OS: Linux

Workaround: claude --resume <session-id> works

Investigation Findings:

• Session .jsonl files exist with valid customTitle records
• sessions-index.json is stale (4 entries vs 15+ session files)
• Deleting the index doesn't fix it
• Issue has occurred multiple times

Affected Sessions:

• afad0c28-73d4-4495-9c3a-cccbf8174508 - "Vertex Setup" (29MB)
• f3b74e4c-71d8-4ca9-90a8-efd333787871 - "create new docker images and gitlab pipeline" (2.4MB)

What Should Happen?

Expected: Named session appears in picker
Actual: Session does not appear

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce:

1. Start a Claude Code session
2. Rename it with /rename my-session-name
3. Exit and start a new session
4. Run /resume

Claude Model

Opus

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

Claude Code version: 2.1.31

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Warp

Additional Information

_No response_